{"title":"大色数有向图中具有同余约束的细分","authors":"Raphael Steiner","doi":"10.1002/jgt.23020","DOIUrl":null,"url":null,"abstract":"<p>We prove that for every digraph <math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>F</mi>\n </mrow>\n </mrow>\n <annotation> $F$</annotation>\n </semantics></math> and every assignment of pairs of integers <math>\n <semantics>\n <mrow>\n <msub>\n <mrow>\n <mo>(</mo>\n <mrow>\n <msub>\n <mi>r</mi>\n \n <mi>e</mi>\n </msub>\n \n <mo>,</mo>\n \n <msub>\n <mi>q</mi>\n \n <mi>e</mi>\n </msub>\n </mrow>\n \n <mo>)</mo>\n </mrow>\n <mrow>\n <mi>e</mi>\n \n <mo>∈</mo>\n \n <mi>A</mi>\n <mrow>\n <mo>(</mo>\n \n <mi>F</mi>\n \n <mo>)</mo>\n </mrow>\n </mrow>\n </msub>\n </mrow>\n <annotation> ${({r}_{e},{q}_{e})}_{e\\in A(F)}$</annotation>\n </semantics></math> to its arcs there exists an integer <math>\n <semantics>\n <mrow>\n <mi>N</mi>\n </mrow>\n <annotation> $N$</annotation>\n </semantics></math> such that every digraph <math>\n <semantics>\n <mrow>\n <mi>D</mi>\n </mrow>\n <annotation> $D$</annotation>\n </semantics></math> with dichromatic number greater than <math>\n <semantics>\n <mrow>\n <mi>N</mi>\n </mrow>\n <annotation> $N$</annotation>\n </semantics></math> contains a subdivision of <math>\n <semantics>\n <mrow>\n <mi>F</mi>\n </mrow>\n <annotation> $F$</annotation>\n </semantics></math> in which <math>\n <semantics>\n <mrow>\n <mi>e</mi>\n </mrow>\n <annotation> $e$</annotation>\n </semantics></math> is subdivided into a directed path of length congruent to <math>\n <semantics>\n <mrow>\n <msub>\n <mi>r</mi>\n \n <mi>e</mi>\n </msub>\n </mrow>\n <annotation> ${r}_{e}$</annotation>\n </semantics></math> modulo <math>\n <semantics>\n <mrow>\n <msub>\n <mi>q</mi>\n \n <mi>e</mi>\n </msub>\n </mrow>\n <annotation> ${q}_{e}$</annotation>\n </semantics></math>, for every <math>\n <semantics>\n <mrow>\n <mi>e</mi>\n \n <mo>∈</mo>\n \n <mi>A</mi>\n <mrow>\n <mo>(</mo>\n \n <mi>F</mi>\n \n <mo>)</mo>\n </mrow>\n </mrow>\n <annotation> $e\\in A(F)$</annotation>\n </semantics></math>. This generalizes to the directed setting the analogous result by Thomassen for undirected graphs, and at the same time yields a novel short proof of his result.</p>","PeriodicalId":16014,"journal":{"name":"Journal of Graph Theory","volume":"105 1","pages":"136-143"},"PeriodicalIF":0.9000,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jgt.23020","citationCount":"3","resultStr":"{\"title\":\"Subdivisions with congruence constraints in digraphs of large chromatic number\",\"authors\":\"Raphael Steiner\",\"doi\":\"10.1002/jgt.23020\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>We prove that for every digraph <math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>F</mi>\\n </mrow>\\n </mrow>\\n <annotation> $F$</annotation>\\n </semantics></math> and every assignment of pairs of integers <math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mrow>\\n <mo>(</mo>\\n <mrow>\\n <msub>\\n <mi>r</mi>\\n \\n <mi>e</mi>\\n </msub>\\n \\n <mo>,</mo>\\n \\n <msub>\\n <mi>q</mi>\\n \\n <mi>e</mi>\\n </msub>\\n </mrow>\\n \\n <mo>)</mo>\\n </mrow>\\n <mrow>\\n <mi>e</mi>\\n \\n <mo>∈</mo>\\n \\n <mi>A</mi>\\n <mrow>\\n <mo>(</mo>\\n \\n <mi>F</mi>\\n \\n <mo>)</mo>\\n </mrow>\\n </mrow>\\n </msub>\\n </mrow>\\n <annotation> ${({r}_{e},{q}_{e})}_{e\\\\in A(F)}$</annotation>\\n </semantics></math> to its arcs there exists an integer <math>\\n <semantics>\\n <mrow>\\n <mi>N</mi>\\n </mrow>\\n <annotation> $N$</annotation>\\n </semantics></math> such that every digraph <math>\\n <semantics>\\n <mrow>\\n <mi>D</mi>\\n </mrow>\\n <annotation> $D$</annotation>\\n </semantics></math> with dichromatic number greater than <math>\\n <semantics>\\n <mrow>\\n <mi>N</mi>\\n </mrow>\\n <annotation> $N$</annotation>\\n </semantics></math> contains a subdivision of <math>\\n <semantics>\\n <mrow>\\n <mi>F</mi>\\n </mrow>\\n <annotation> $F$</annotation>\\n </semantics></math> in which <math>\\n <semantics>\\n <mrow>\\n <mi>e</mi>\\n </mrow>\\n <annotation> $e$</annotation>\\n </semantics></math> is subdivided into a directed path of length congruent to <math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mi>r</mi>\\n \\n <mi>e</mi>\\n </msub>\\n </mrow>\\n <annotation> ${r}_{e}$</annotation>\\n </semantics></math> modulo <math>\\n <semantics>\\n <mrow>\\n <msub>\\n <mi>q</mi>\\n \\n <mi>e</mi>\\n </msub>\\n </mrow>\\n <annotation> ${q}_{e}$</annotation>\\n </semantics></math>, for every <math>\\n <semantics>\\n <mrow>\\n <mi>e</mi>\\n \\n <mo>∈</mo>\\n \\n <mi>A</mi>\\n <mrow>\\n <mo>(</mo>\\n \\n <mi>F</mi>\\n \\n <mo>)</mo>\\n </mrow>\\n </mrow>\\n <annotation> $e\\\\in A(F)$</annotation>\\n </semantics></math>. This generalizes to the directed setting the analogous result by Thomassen for undirected graphs, and at the same time yields a novel short proof of his result.</p>\",\"PeriodicalId\":16014,\"journal\":{\"name\":\"Journal of Graph Theory\",\"volume\":\"105 1\",\"pages\":\"136-143\"},\"PeriodicalIF\":0.9000,\"publicationDate\":\"2023-08-07\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jgt.23020\",\"citationCount\":\"3\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Graph Theory\",\"FirstCategoryId\":\"100\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1002/jgt.23020\",\"RegionNum\":3,\"RegionCategory\":\"数学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"MATHEMATICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Graph Theory","FirstCategoryId":"100","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/jgt.23020","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATHEMATICS","Score":null,"Total":0}
Subdivisions with congruence constraints in digraphs of large chromatic number
We prove that for every digraph and every assignment of pairs of integers to its arcs there exists an integer such that every digraph with dichromatic number greater than contains a subdivision of in which is subdivided into a directed path of length congruent to modulo , for every . This generalizes to the directed setting the analogous result by Thomassen for undirected graphs, and at the same time yields a novel short proof of his result.
期刊介绍:
The Journal of Graph Theory is devoted to a variety of topics in graph theory, such as structural results about graphs, graph algorithms with theoretical emphasis, and discrete optimization on graphs. The scope of the journal also includes related areas in combinatorics and the interaction of graph theory with other mathematical sciences.
A subscription to the Journal of Graph Theory includes a subscription to the Journal of Combinatorial Designs .